Threaded stud and nut actuated quick-set clamp



Aug. 28, 1956 D. Mx-:RTZ 2,760,535

THREADED STUD AND NUT ACTUATED QUICK-SET CLAMP med sept. e, 1952 DAVID MERTZ BYW n' AT RNEYS nited States Patent O THREADEDSTUD AND NUT ACTUATED QUICK-SET .CLAMP David Mertz, Detroit, Mich.

Application September, 1952, Serial No. 308,380

1 Claim. (Cl. 144-303) The present invention relates to .a .quick-set clamping .device which may be quickly moved Vinto engagement with a piece -to be clamped, and .thereafter operated to exert relatively great clamping pressure thereon with a minimum of time and effort. n

For simplicity and ready explanation, the 4device is herein illustrated and described as a single clamping member associated with a base having a fixed head or anvil thereon. However, it will be obvious that if desired, two or more clamping devices may be associated together which are independently movable toward and away from each other in the same or parallel or converging T-slots or the like. Thus, three such clamping devices may be used with intersecting T-slots on the bed of a machine tool to position a workpiece with exactitude.

Moreover, a single clamping member may have associated therewith one or more lock members connected together by a plurality of clamping means.

It is an object of the present invention to provide a quick-set clamp characterized by its adaptability to be moved major distances by simple sliding movement and then to be clamped against a workpiece with a minimum of time and effort.

It is a further object of the present invention to provide a quick-set clamp comprising a single actuating device operable sequentially to lock the clamp in approximate clamping position and then to move the clamp in clamping relation.

It is a further object of the present invention to provide a quick-set clamp characterized by its simplicity, ruggedness, ease of operation, and eiecfiveness.

It is a further object of the present invention to provide a clamp characterized by its ability to develop relatively great clamping pressures while minimizing any tendency to distort the base or frame.

Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings, wherein:

Figure l is a plan view of a single embodiment of clamp.

Figure 2 is a vertical median section of the clamp.

Figure 3 is a fragmentary bottom plan view of the clamp.

Figure 4 is a section on the line 4 4, Figure 2.

Figure 5 is a fragmentary perspective of the modified form of nut.

As shown in the simplied embodiment of the invention chosen for illustration, there is provided a base having an elongated slot 12, adjacent one end of which is a fixed head or anvil 14. The outer surfaces of said base at opposite sides of said slot are smooth as indicated at 16. However, at the inner surfaces of said base at opposite sides of said slot, serrated surfaces 18 are provided, and this is most eiciently accomplished by forming the serrations on a separate slotted lock strip 20 which as illustrated is retained in position by set screws 22.

Slidably mounted on the smooth surfaces 16 is a jaw member 24 having a guide key 26 received in the slot 12.

Y 2,760,535 .Patented Aug. 281, 1956 2 The jaw r24is movable-toward and away from the anvil 14 and is adapted to clamp a work piece W. The yjaw 24 has anopeiing 28 Aextending obliquely therethrough, the openingbeing laterally enlarged inthe plane of Figure`2. Extending through the opening is a socket headed stud 30, which'is -rocka'ble lin the'opening 28.

At the inner side o'fthe'slot 12tt'here isprovided alock member 32 which s pansthe-slot and has-aiserrated surface engageable-With the serrations of the-surfaces 1'8'to retain the lock againsttmovementalongthe slot. As illustrated, the serrations are symmetrical 60 serrations `but while this voffers some definite advantages, the langle of the serrations may be varied'and they need not be symmetrical. The pitch of :the lserrations in apractical embodiment of the .invention -was 1/16 vof an inch, but the essential requirement 4is `only that the pitch 1be related to ythe longitudinal vadjustment of the jaw at each-setting ysuchthat-clamping pressure maybe applied `yby ythej'jaw in anyposition along the slot.

At its lower side '-'the lock S2is providedwith a recess ror `seat 34 `which -is Lhereinillustrated as spherical. Located in the seat 34 is a nut 36, also spherically formed. The nut is thus rockable in the seat. The nut has a slot 38 formed therein, and the end 40 of a set screw 42 enters the slot to hold the nut in place and to prevent rotation.

In Figure 5 there is illustrated at 44 a different form of nut which is cylindrically shaped and is adapted to seat in a correspondingly shaped cylindrical seat. The cylindrical nut 44 of course requires no separate means to prevent its rotation.

The threaded stud 30 engages the nut 36 (or 44) and when rotated by a tool draws the lock 32 and jaw 24 toward each other. When this takes place, the serrations on the lock engage the serrations on the surface 18 and prevent movement of the lock longitudinally of the slot 12. Further actuation of the stud moves the jaw along the surface 16 of the base in a direction to decrease the separation between lock 32 and jaw 24 longitudinally of the slot 12. This is accompanied by rocking of the stud 30 in the plane of Figure 2.

In order to prevent engagement between the serrated surfaces of the lock and lock strip when the stud is loosened and major adjustments of the jaw are required, the lock 32 is provided with spring pressed, round or smooth headed pins 46 which are interposed between the respective serrated surfaces.

ln order to provide for automatic relative positioning of the jaw 24 and lock 32 when the stud is loose such as to provide for maximum clamping movement of the jaw after the lock is seated in the serrated surface 18, resilient means are provided to rock the stud 30 in a direction to increase the separation between jaw and lock longitudinally of the slot 12. This comprises a plug 48 of soft metal engaging the stud and received in a bore 50 in the jaw 24. The bore 50 is threaded and receives a threaded plug 52, and between the plugs 52 and 48 is a compression spring 54. This rocks stud 30 clockwise as seen in Figure 2, about an axis adjacent the head of the stud, and assuming the jaw 24 to be stationary, results in movement of the lock 32 to the left in this figure.

From the foregoing it will be seen that when the stud is loosened suiciently, the entire sub-assembly comprising the jaw, stud and lock, may be moved with substantial freedom along the slot to any desired position. However, when the stud is tightened, the lock first engages the serrated surface 18, and thereafter the jaw is forced to move along the slot in clamping relation.

The angle of obliquity of the stud 30 relative to the plane of the base 10 is herein shown as about 45 but this angle may be varied in accordance with the specific problems to be anticipated. In general however, this angle should be approximately in the range of 40-50.

Attention is directed to the fact that any tendency to distort the frame when relatively great clamping pressures are exerted is minimized, due to the fact that the jaw 24 and lock 32 overlie each other-at the outer and inner sides of the slot 12. g

The drawings and the foregoing specication constitute a description of the improved quick-set clamp in such full, clear, concise and exact terms as toenable any person skilled in the art to practice the invention, the scope'of which is indicated by the appended claim.

What IV claim as my invention is:

A quick set clamping device comprising a base having an elongated slot therein, the surfaces at the outer side of said base at opposite sides of said slot being smooth,

the surfaces at the inner side of said base at opposite sides of said slot having servies of longitudinally spaced lock seats, a xed jaw on said base at one end of said slot, a movable jaw member spanning said slot and having portions slidable along said smooth surfaces at the outer side of said base and a guide key slidably received'in said slot, an adjustable lock member spanning said slot at the inner side of said base and having parts receivable in said seats to provide for step-by-step positioning of said lock member along said slot, a nut carried by saidlock member,

said jaw member having an enlarged opening therethrough, a headed stud extending through the opening in said jaw member and angularly movable relative thereto in a plane extending longitudinally through said slot and about an axis located substantially at the head thereof, means connecting said nut to said lock member for relative rocking movement in theplane of said slot, means p preventing rotation of said nut about the axis of its threads, said stud being threadedly engaged in said nut and extending obliquely to the length of said slot.

References CitedV in the le of this patent UNITED STATES PATENTS 131,195 Traut 2- Sept. 10, 1872 220,145 Heckendorn Sept. 30, 1879 292,391 Weiser Jan. 22 1884 540,413 Vanderbeek June 4, 1895 900,915 vCurnner Oct. 13, 1908 970,568 Starrett Sept. 20, 1910 1,039,337 Vanderbeek Sept. 24, 1912 1,114,970 Cumner Oct. 27, 19.14 V1,269,262 Crawford .Tune 11, 1918 2,552,738 Renner May 15, 1951 

